Time-Space Coded Structured Light Depth Measurement
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Solution Overview
Problem
Existing structured light-based depth perception technologies require multiple projectors for different coded patterns, increasing development costs and algorithm complexity, and affecting the accuracy and robustness of three-dimensional depth measurement.
Innovation Solution
A time-space coding method and apparatus that generates different coded patterns in time division by driving light-emitting points on a regular light-emitting lattice, using a single projector for time-space labeling, and employing a depth decoding algorithm to improve accuracy and robustness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple coded pattern projectors are used to project different coded patterns, then the depth measurement coverage and accuracy are improved, but the device complexity and calibration difficulty increase significantly
Solution Approach 1:
The patent segments the coded pattern projection into two independent parts: (1) a fixed coded pattern projected by a single projector, and (2) a dynamic modulation pattern projected by a spatial light modulator. This segmentation allows the system to achieve multi-pattern projection capabilities without adding multiple physical projectors, thereby reducing device complexity while maintaining depth measurement accuracy.
Solution Approach 2:
The spatial light modulator serves multiple functions: it modulates the fixed coded pattern from the single projector to generate multiple time-varying coded patterns, performs time-space encoding, and enables different coding strategies (e.g., M-array, phase-shifting). This multi-functionality eliminates the need for multiple dedicated projectors for different coding schemes, simplifying the overall system while preserving measurement precision.
2Measurement precision
If different coded patterns are designed for different application scenarios, then the adaptability and measurement precision are improved, but the manufacturing cost and development time increase
Solution Approach 1:
The patent transforms static coded patterns into dynamic modulated patterns by introducing a spatial light modulator that can rapidly switch between different coding patterns in time division multiplexing mode. This dynamic capability allows a single projector system to adapt to different application scenarios (different depth ranges, resolutions, and measurement speeds) without requiring separate hardware designs for each scenario, thereby reducing development costs and time.
Solution Approach 2:
The system changes the temporal and spatial parameters of the coded patterns through electronic control of the spatial light modulator, rather than physically redesigning patterns for different applications. By adjusting modulation frequency, pattern type, and projection timing, the system adapts to various measurement requirements without incurring additional manufacturing or development costs.
3Productivity
If multiple coded patterns are projected simultaneously, then the depth measurement efficiency is improved, but the algorithm complexity and computation burden increase
Solution Approach 1:
The patent employs periodic modulation of coded patterns in time division multiplexing, where each coded pattern is projected for a specific time interval in a repeating sequence. This periodic action enables the decoding algorithm to process patterns sequentially rather than simultaneously, reducing computational complexity while maintaining measurement efficiency. The time-varying nature of patterns provides unique temporal signatures that simplify the matching and depth calculation processes.
Data Source
AI summary
The present disclosure provides a time-space coding method and apparatus for generating a structured light coded pattern. Different coded patterns are outputted in time division by driving different light-emitting points based on a regular light-emitting lattice so as to time-space label a target object or a projection space. This method effectively overcomes the limitations of the fact that in the prior art, a plurality of projectors is needed to project different patterns in time division when it is required to project time-space labels of a plurality of patterns. According to the present method, by driving different light-emitting elements on the light-emitting substrate, different coded patterns are formed, and by using a time-division output technology, time-space labeling of an object may be finalized with only one projector. Moreover, this method may significantly improve the accuracy and robustness of three-dimensional depth measurement through time-space coding with a depth decoding algorithm.